Snowplow blade

ABSTRACT

In a snowplow blade, an upper elongated rolling element is associated with a lower elongated knife having a free sliding lower edge, in use, in contact with a surface to be cleared; the knife comprising a plurality of elongated plate portions independent from one another and juxtaposed in a direction transverse to the advancement direction of the blade; at least a guide and slide assembly of relative mobility being interposed between each elongated plate portion and the rolling element to allow at least a translation of the elongated plate portion towards the rolling element against the action of at least one removal elastic block of the plate portion from the rolling element itself.

TECHNICAL FIELD

The present invention relates to a snowplow blade adapted to be driven by a self-propelled unit to remove snow or ice from a surface to be cleared, for example a road surface, to which the ensuing treatment will make explicit reference, without this implying any loss in generality.

BACKGROUND ART

In particular, the present invention relates to a snowplow blade of the type comprising a mounting frame to the self-propelled unit, an upper rolling element coupled to the mounting frame and a lower road surface scraping knife. The known blades of the type described above operate in a satisfactory manner when the road surface is flat, whereas they are found to be poorly efficient when the road surface has concavities and/or convexities or longitudinal bumps. In fact, in presence of non-flat road surfaces, indicated in the jargon as “horseback surfaces”, a segment or segments of the straight lower edge of the knife slide in contact with the raised portions of the surface, other segments remain vertically separated from other corresponding lower portions of the surface itself inevitably leaving on the lower portions themselves a layer of compacted snow intolerable for security issues.

DISCLOSURE OF INVENTION

An object of the present invention is to obtain a snowplow blade, which allows to solve in a simple and economical way the above exposed problems and, in particular, to obtain a uniform clearing of the road surface independently from the state of the road surface itself.

According to the present invention a snowplow blade is obtained, comprising a mounting frame to a self-propelled advancement unit of the blade itself above a surface to be cleared, an upper elongated rolling element carried by said frame and an elongated lower knife constituting a downward extension of the upper rolling element and having a free sliding lower edge, in use, in contact with said surface to be cleared; the lower knife comprising at least two elongated plate portions independent of one another and aligned in a direction transverse to the advancement direction of the blade; characterized by also comprising, for each of said elongated plate portion, at least a respective guide and slide assembly adapted to allow at least a translation of the respective said elongated plate portion to and from said rolling element with respect to the other of said elongated plate portions and elastic thrust means interposed between each of said elongated plate portion and the rolling element to space the elongated plate portion from the rolling element.

Preferably, the blade defined above also comprises, for each of said elongated plate portion, at least one pair of said guide and slide assemblies spaced from one another along the respective elongated plate portion in said cross direction.

Preferably, moreover, the blade defined above comprises, again, for each of said plate portions, at least one hinge adapted to allow, in use, a rotation of the respective said elongated plate portion with respect to the other said elongated plate portion about an axis of instantaneous rotation substantially orthogonal to the respective said elongated plate portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described with reference to the accompanying drawings, which illustrate non-limiting embodiment, wherein:

FIG. 1 is a perspective view of a preferred embodiment of a snowplow blade obtained according to the dictates of the present invention coupled to a thrust tractor;

FIG. 2 illustrates, in side elevation and on an enlarged scale with parts removed for clarity, the snowplow blade of FIG. 1;

FIG. 3 illustrates, in section and on an enlarged scale, a detail of FIG. 2;

FIG. 4 is a front view with parts removed for clarity of the snowplow blade of FIG. 1;

FIG. 5 is an enlarged perspective view of a detail of FIGS. 3 and 4; and

FIG. 6 is a figure similar to FIG. 3 and illustrates a variant of a detail of FIG. 3.

BEST MODE FOR CARRYING OUT THE INVENTION

In FIG. 1, 1 indicates, as a whole, a snowplow blade adapted to be advanced above a surface 2 to be cleared, generally a road surface or a square, by self-propelled unit 3, schematically illustrated and known per se.

The blade 1 comprises a mounting frame 4 to the self-propelled unit 3, an elongated rolling element 5, known per se and not described in detail, coupled to the frame 4 in a rotating manner about an axis 7 substantially orthogonal to the surface 2 under the thrust of actuators 6.

The blade 1 also comprises a pair of support wheels or vertical reference, known per se and not visible in the attached figures, disposed in the vicinity of the frame 4 and in the rear of the rolling element 5 to rotate in contact with the surface 2 cleared by blade 1.

The blade 1 comprises, finally, an elongated knife 8, which is disposed below the rolling element, constitutes a downward extension of the rolling element 5 and terminates below with a sliding edge 9, in use, in contact with the surface 2.

As can be seen from FIGS. 1 and 4, the knife 8 is constituted by a row 10 of modules 11 independent from one another and juxtaposed one to the other.

Each module 11 comprises a flat elongated plate 12, which is conveniently made of metallic material and, in a scraping condition, illustrated in FIGS. 1 to 3, is juxtaposed and aligned to the other plates 12 in a rectilinear direction 13 (FIG. 1) transverse to an advancement direction of the blade 1, orthogonal to the axis 7 and substantially parallel to a generatrix of the rolling element 5 to define a portion of the knife 8.

Each module 11 comprises, furthermore, a supporting guide and slide assembly 15 thereof of the respective plate 12 and a mounting plate block 16, elastically yielding, of the assembly 15 to the rolling element. In particular, each block 16 has an upper end firmly connected to a lower end portion of the rolling element 5 by means of respective bolts 18 and a lower end firmly connected to the guide and slide assembly 15 by means of respective bolts 19. Each plate block 16 is dimensioned so as to maintain the relative plate 12 in a scraping operative advanced position, illustrated in FIGS. 1 and 4, and allow the backward rotation of the relative assembly 15 and of the relative plate 12 with respect to the rolling element 5 about a hinge axis 20 parallel to the rectilinear direction 13 and orthogonal to axis 7 when the plate 12 meets on the surface 2 a fixed located obstacle.

According to a variation not illustrated, each block 16 is replaced by a mechanical hinge and a forcing elastic element and preloaded the hinge to maintain the plate in the scraping operative position.

Still with reference to FIGS. 1 and 2 and, in particular, to FIG. 3, each assembly 15 comprises a flat rear metal plate 22 disposed partially in abutment on a front surface of the respective block 16 and a flat front metal plate 23 disposed parallel one another and spaced from each other by an upper, spacer 24 of an amount approximately rounded up to the thickness of the relative plate 12.

The plates 22 and 23 the spacer 24 and the block 16 are pack-tightened one another by the bolts 19. The plates 22 and 23, the spacer 24 and the block 16 delimit one another a seat 27 open downwards, in which an upper portion 12 a of the relative plate 12 is slidably inserted, the remaining portion 12 b thereof projects downwards in a cantilever manner beyond the plates 22 23 themselves.

Each assembly 15 comprises, furthermore, a further row of bolts 28 disposed below the bolts 19 and crossing both plates 22 and 23. Each bolt 28 also crosses a respective slot 30, which is elongated in a substantially vertical direction and is attained in the upper portion 12 a of the plate 12. Preferably, each slot has a length measured in a substantially vertical direction variable between 15 and 35 millimeters, conveniently 20 millimeters, and houses with radial play a respective bushing or sleeve 31, in turn crossed with radial play by the stem of the respective bolt 28.

With explicit reference to FIG. 4, each upper portion 12 a is delimited on the side facing the spacer 24 by a peripheral surface 33, which delimits with the spacer 24 itself and with part of the plates 22 and 23 an elongated chamber 35, in which a plurality of elastic bodies 36 conveniently made of a single piece of elastomeric material is housed, preferably a polyurethane material and independent from one another.

Each elastic body 36 is retained in an operative position thereof, spaced from the other bodies 36 by prominences 37 protruding, in the particular example described, both from the plate 12 and from the spacer 24.

Also in the particular example described, each body 36 has an inverted eight shape and comprises two tubular portions 39, which are connected one another by a transverse arm 40 and have respective axes 41 orthogonal to the plates 12,22 and 23 and parallel one another and to bolts 18,19 and 28.

The tubular portions 39 have outer diameters greater than the maximum distance d (FIG. 4) of the surface 33 from the spacer 24 so as to push and maintain the respective plate 12 in an extracted position and the bushings 31, together with the stems of the bolts 28 to the upper end of the relative slots 30 (FIG. 4).

According to variations not shown, the bodies 36 of elastomeric material are not made in one piece have different geometries with respect to that indicated by way of example, or are in whole or in part replaced by other elastic elements such as, for example, coil compression springs or leaf springs or other equivalent component elastically yielding.

In use, i.e. when the plates 12 scrape the surface 2, the elastic bodies 36, independently of whether elastomeric or metal or a combination thereof, by deforming elastically, each, according to the action received from the respective underlying portion of the plate 12 allow the plate 12 itself to translate or slide within the seat 27 towards the roiling element 5 in a substantially rectilinear direction and/or rotate with respect to the plates 22 and 23 for coupling effect with the play of the plates 22 and 23 themselves to the respective bolts 28, about an instantaneous rotation axis orthogonal to the plates 12, 22 and 23 and substantially parallel to the bolts 19 and 28.

In this way, each plate 12 according to the entity of the thrust received by the underlying portion of the surface 12 determined by the geometry of the portion of the surface itself moves with respect to the rolling element 5 and with respect to the other plates 22 and 23 and following the profile of the surface 12 so that, in use, the lower edge 9 of the knife 8 is found to be rectilinear in case the knife 8 itself slides on a flat surface and at a broken curve when it slides in contact with convex or bumpy surfaces. In both cases, the knife 8 adapting to the geometry of the surface 12 to be cleared clears in the same way any area of the surface 12 itself.

According to a first variant, each block 16 is a rigid block adapted to connect permanently and integrally the respective assembly 15 to the rolling element 5. Alternatively, each plate 22 is directly and permanently connected to the rolling element 8.

In both cases, between the rolling element 5 and the frame 4 elastically yielding means are provided, and known per se, adapted to allow the backward rotation of the rolling element 5 together with the knife 8 about a hinge, axis practically parallel to the rectilinear direction 13 when the knife 8 meets on the surface 2 a fixed located obstacle.

According to a further variant illustrated in FIG. 6, the blocks 16 are replaced by a rigid load-bearing or support structure 45, which is common to, and supports all, assemblies 15, and is hinged to the rolling element 5 by means of a hinge 46 elastically preloaded by an elastic device, preferably with wire springs or elastomeric material, generically indicated with 48, to maintain the structure 45 in a reference or limit operating advanced position and allow the structure 45 itself and to the plates 9 to rotate simultaneously backwards with respect to the rolling element 5 about a common hinge axis 47 parallel to the rectilinear direction 13 in the presence of fixed obstacles on the surface 2 to be cleared.

From the foregoing it will be evident that the blade 1 described may be made to further modifications and variations which do not depart from the protective scope defined by the independent claim. In particular, the knife 8 could include a number of modules or plates 9 different from that illustrated and for example only two modules and therefore also only two independent plates, although it is obvious that the greater the number of plates 12 the better the knife edge 8 approximates the curvature of the surface 2 and the more accurate is the clearing of the surface 2 itself.

Finally, at least part of the guide and slide devices 15 may be shaped so as to allow only the translation of the relative plate 12 from and to the rolling element 5.

In particular, the plates 12 may be coupled to the rolling element 5 in order to translate or slide only from and to the rolling element 5 itself. In this condition, the lower edge of the knife 8 approximates, in use, the curvature of the surface 12 to be cleared, thereby clearing the surface 12 in a rough but still acceptable manner. Obviously, both in such condition and in the case of roto-translation of the blades 12 above described, the clearing of the surface 12 is much better, the greater the number of units 11 and therefore the greater the number of plates 12. 

1. A snowplow blade comprising a mounting frame to a self-propelled advancement unit of the blade itself above a surface to be cleared, an upper elongated rolling element carried by said frame and an elongate lower knife constituting a downwards extension of the upper rolling element and having a free sliding lower edge, in use, in contact with said surface to be cleared; the lower knife comprising at least two elongated plate portions independent of one another and aligned in a direction transverse to the advancement direction of the blade; and, for each of said elongated plate portion, at least a respective guide and slide assembly adapted to allow at least a translation of the respective said elongated plate portion to and from said rolling element with respect to the other of said elongated plate portions and elastic thrust means interposed between each of said elongated plate portion and the rolling element to space the elongated plate portion from the rolling element, characterized by comprising, in addition, for each of said elongated plate portion, at least one respective hinge adapted to allow, in use, a rotation of the respective said elongated plate portion with respect to the other of said elongated plate portions about an axis of instantaneous rotation substantially orthogonal to the respective said elongated plate portion.
 2. The blade according to claim 1, characterized by comprising, for each of said elongated plate portion, at least one pair of said guide and slide assemblies spaced from one another along the respective elongated plate portion in said cross direction.
 3. The blade according to claim 1, characterized by comprising one of said hinges for each of said guide and slide assembly.
 4. The blade according to claim 1, characterized in that said elastic thrust means retain the respective said elongated plate portion in an extracted limit position.
 5. The blade according to claim 1, characterized in that said elastic means comprise at least one block of elastically deformable material forced between a terminal edge of the respective elongated plate portion and a reference body carried by said rolling element.
 6. The blade according to claim 5, characterized in that said block of elastically deformable material is forced between an upper end surface of the respective said elongated plate portion and an abutment surface of the said reference body.
 7. The blade according to claim 5, characterized in that said elastic means comprise, for each of said elongated plate portion, a plurality of said blocks of elastically deformable material distributed along the length of said elongated plate portion.
 8. The blade according to claim 6, characterized in that each of said block comprises at least one tubular portion having an axis orthogonal to the respective said elongated plate portion.
 9. The blade according to claim 1, characterized in that each of said guide and slide assembly comprises two guide plates substantially flat, parallel and facing one another accommodating between each other in a sliding manner a flat upper end segment of the respective said elongated plate portion, a first of said plates being connected to said rolling element.
 10. The blade according to claim 9, characterized in that each of said guide and slide assembly also comprises a respective reference pin carried by one of said plates and a slot formed on said plate portion and engaged with clearance by said pin.
 11. The blade according to claim 9, characterized by comprising, furthermore, hinge means interposed between said rolling element and said first plate to allow the respective said elongated plate portion to rotate backwards with respect to the rolling element around a hinge axis parallel to said transverse direction independently of the other elongated plate portions.
 12. The blade according to claim 9, characterized in that said first plate is integrally connected to said rolling element.
 13. The blade according to claim 9, characterized in that said first plates are carried by a common support structure, and in that it also comprises additional hinge means interposed between said rolling element and said common support structure to allow said elongated plate portions to simultaneously rotate with respect to the rolling element around a common hinge axis parallel to said transverse direction; elastic means being provided for maintaining said common structure in an angular reference position.
 14. The blade according to claim 1, characterized in that said knife comprises a plurality of said elongated plate portions independent from one another. 